Fluid fuel injection apparatus for blast furnace



E. A. COSTENBADER ETAL 3,186,471-

FLUID FUEL INJECTION APPARATUS FOR BLAST FURNACE Filed Aug. 7. 1962 June1, 1965 INVENTORS Ead A. Cos/enbqder Pair/bk 6. Dur/rin United StatesPatent 3,186,471 FLUID FUEL INJECTION APPARATUS FOR BLAST FURNACE EarlA. Costenbader and Patrick G. Durkin, Baltimore, Mcl., assignors, bymesne assignments, to Bethlehem Steel Corporation, a corporation ofDelaware Filed Aug. 7, 1962, Ser. No. 215,417 3 Claims. (Cl. 158-76)This invention is a device for the injection of fuel or other materialsinto a blowpipe of a blast furnace.

It is an object of this invention to provide a fuel injection devicewhich functions satisfactorily in operation while enabling repairs orsubstitutions to be made quickly, safely, inexpensively and easily.

Another object is to provide an adjustable pressure seal.

Other objects, purposes and advantages of this invention will appearhereinafter in the specification and claims, and in the appendeddrawings.

In the drawings:

FIGURE 1 is a side elevation of our fuel injection device in operatingposition in a blast furnace blowpipe; and

FIG. 2 is a top sectional detail view of the invention.

In the conventional construction of a blast furnace for producing pigiron, the lower portion which serves a receptacle for the molten metaland slag is the hearth. This is built of firebrick and is externallyreinforced by a circumferential metal jacket 2. The hot air of the blastis admitted to the furnace through a plurality of tuyeres 3 which arehollow copper castings inserted in tuyere coolers 4 positionedsymmetrically around the circumference of the hearth.

The blowpipe 5 thereto is usually a horizontal cast iron pipe, throughwhich the hot blast is delivered to the tuyere 3 from the dependingL-shaped tuyere stock 6. The forward end of said tuyere stock 6 may beturned to fit closely into socket 7 in the blowpipe 5.

The blowpipe is held in place with its forward or smaller end fittinginto socket 8 of the tuyere by pressure from the tuyere stock 6, whichis suspended by conventional means attached to its upwardly extendingportion and is provided on its lower portion with a depending lug 9having a hole 10 through which an end-threaded connecting rod 11provided with a heavy coiled spring 12 extends to another lug 13 on thehearth jacket 2' where it is anchored. A large nut 14 of stainless steelor brass on the outer end of the rod 11 will enable adjustment of thespring to create the desired pressure while allowing for motion due tocontraction and expansion.

In the preferred embodiment of this invention, the shell 15 of theblowpipe 5 has mounted on its exterior side surface a sloping metalblock or sleeve 16 having a rearwardly flared seat 17 and a forwardlyinclined hole or passage 18 communicating with a correspondinglyinclined hole or passage 19 in the forward portion of the shell, and aU-shaped lug 20, having a slot 21, in alignment with, the block on therear portion of the shell.

Insertable into said blowpipe 5 through the flared seat 17 and passages18 and 19 is the pipe nozzle 22. Said nozzle is a heavy stainless steelpipe of about 'Vs" inside diameter, the forward end of which slidablyprojects inwardly at an angle of about 20 between the central axes ofsaid pipe nozzle 22 and of the blow pipe 5, and extends to the front endof the shell 15, for a suflicient distance to inject the fuel at thecenter axis of the inner end of the tuyere 3. The rear end of saidnozzle 22 is externally threaded and screws into a conical collar orferrule 23 which engages in the flaring seat 17. The surface of :seat 17forms an angle of approximately with the central axis of nozzle 22.

3,186,471 Patented June 1, 1965 "ice Welded at an angle to the outerface 24 of said collar 23 is the oil supply pipe 25, which later has aside nipple 26 before the closure plug 27 and a slotted end 28. Theassembly is held in place by the wedge key 29 which 1s driven againstthe slotted pipe end 28 into the slot 21 in the U-shaped lug 20. Duringthe operation of the furnace, lengthening of the blowpipe shell 15 dueto expansion, such as may result from an increase in the hot blast airtemperature or the like, can break the seal between seat 17 and ferrule23, because the fuel pipe 25 is normally at a lower temperature thansaid shell. The fluid seal may then be reformed by hammering wedge key29 so as to force the ferrule and seat back into sealing contact.

To afford proper clearance from and access to other parts of the blastfurnace, and also to diminish the discomfort to workmen from excessiveheat, it will be found preferable in most installations for theapparatus to be mounted on the more accessible side of the blowpipe 5,as shown, but the device may obviously be mounted on the top or bottomof the blowpipe where this is convenient or desired.

As the nozzle does not extend for more than about a" third of the lengthof the blowpipe, it has a minimum of exposure to the hot blast, and isalso a safe distance from the nose of the tuyere.

Fuel oil is supplied through a flexible hose (not shown), which may beattached to or removed from the pipe nipple 26 by any standard quicklocking and disconnecting means. The oil feed must of course be entirelydisconnected before the nozzle assembly can be safely installed orremoved. Also, the blast air must be taken off the furnace so that noblow-by can escape through the sleeve 16 and thereby endanger theworkmen. Accordingly, the preferable time for changing these assembliesis directly after a cast.-

The above-described injection device can obviously be adapted to the useof other fluid fuels than oil, including gaseous, liquid, semi-solid, orsolid-in-liquid fuels such as natural or artificial gas, pitch, tar orpowdered coal, singly or combined, or with steam or oxygen, depending ontheir relative delivered costs at the particular location.

We claim:

1. A fuel injection device comprising:

(a) a hollow blowpipe shell,

(b) means forming a first cylindrical passage extending forwardly at anangle through the wall of said blowpipe,

(c) a sleeve mounted on said blowpipe shell having a second cylindricalpassage therethrough in alignment with and communicating with said firstpassage and having a conically flared seat portion therein at the outerend of said second passage,

(d) a slidably insert-able and removable pipe nozzle extending throughboth said passages,

(e) a conical collar concentrically attached to said pipe and seated insaid conically flared end portion in fluid tight relation therewith, andA (f) adjustable wedge means pushing the conical collar intosubstantially gastight engagement with the flared end portion andreleasably securing said collar within the flared portion.

2. A fuel injection device comprising:

(a) a hollow blowpipe shell,

(b) means forming a first cylindrical passage extending forwardly at anangle through the wall of said blowpipe shell,

(-c) a sleeve mounted on said blowpipe shell having a second cylindricalpassage therethrough in alignment with and communicating with said firstpassage and having a conically flared seat portion therein at the outerend of said second passage,

(d) slotted lug means mounted on the blowpipe shell in aligned spacedrelation behind said sleeve,

(e) a slidably insertable and removable pipe nozzle extending throughboth said passages and said sleeve and having a conical collarconcentrically connected to said pipe nozzle and seated in saidconically flared end portion in fluid tight relation therewith,

(f) a fuel supply pipe integrally secured to the outer end of the pipenozzle, and

(g) adjust-able wedge means inserted in the slotted lug in engagementwith the rear end of the fuel supply pipe and thereby holding theconical collar tightly in place in said conically flared end portion ofthe sleeve.

3. A fuel injection device comprising:

(a) a hollow blowpipe shell,

(b) means forming a first cylindrical passage extending forwardly at anangle through the Wall of said shell, p

(c) a sleeve mounted on said blowpipe shell having a second cylindricalpassage therethr-ough in alignment With and communicating with saidfirst passage and having a conically flared seat portion therein at theouter end of said second pass-age,

(d) lug means provided with longitudinally extending slots and mountedon the blowpipe shell in aligned spaced relation behind said sleeve,

(e) a slidably insertable and removable pipe nozzle extending through'both said pass-ages and said sleeve and having a conical collarintegrally concentrically attached to said pipe nozzle and seated insaid coni cally flared seat portion in fluid tight relation therewith,

(f) a fluid fuel supply pipe integrally connected to the outer end ofthe pipe nozzle,

(g) said fluid fuel supply pipe extending rearwardly substantiallyparallel to the blowpipe shell,

(11) said fluid fuel supply pipe having a slotted rear end portion andan inner plug closure and a side JAMES W. WESTHAVER, Primary Examiner.MEYER PERLIN, Examiner.

1. A FUEL INJECTION DEVICE COMPRISING: (A) A HOLLOW BLOWPIPE SHELL, (B)MEANS FORMING A FIRST CYLINDER PASSAGE EXTENDING FORWARDLY AT AN ANGLETHROUGH THE WALL OF SAID BLOWPIPE, (C) A SLEEVE MOUNTED ON SAID BLOWPIPESHELL HAVING A SECOND CYLINDRICAL PASSAGE THERETHROUGH IN ALIGNMENT WITHAND COMMUNICATION WITH SAID FIRST PASSAGE AND HAVING A CONICALLY FLAREDSEAT PORTION THEREIN AT THE OUTER END OF SAID SECOND PASSAGE, (D) ASLIDABLY INSERTABLE AND REMOVABLY PIPE NOZZLE EXTENDING THROUGH BOTHSAID PASSAGES, (E) A CONCIAL COLLAR CONCENTRICALLY ATTACHED TO SAID PIPEAND SEATED IN SAID CONICALLY FLARE END PORTION IN FLUID TIGHT RELATIONTHEREWITH, AND (F) ADJUSTABLE WEDGE MEANS PUSHING THE CONICAL COLLARINTO SUBSTANTIALLY GASTIGHT ENGAGEMENT WITH THE FLARED END PORTION ANDRELEASABLY SECURING SAID COLLAR WITHIN THE FLARED PORTION.